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Optical coupling deviceRelated Patent Categories: Radiant Energy, Photocells; Circuits And Apparatus, Signal IsolatorOptical coupling device description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070187629, Optical coupling device. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO RELATED APPLICATION [0001] This application is based upon and claims the benefit of priority from Japanese Patent Application No. P2005-360422, filed on Dec. 14, 2005, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] An optical coupling device, which is also called a semiconductor relay device, is used in various apparatuses. Above all, the use of the optical icoupling device as a replacement for a mechanical relay of an IC (integrated circuit) tester has recently increased. The main reasons for using the optical coupling device are that the device can provide electrical isolation between an IC to be measured and a system of measurement, and that the device has a long life due to having no contact points. As for another requirement specification, it is desired to achieve an improvement in high-frequency characteristics of the device. [0003] As the operating speed of the IC increases, the operating speed of a signal to be used in the IC tester requires frequencies of the order of several hundreds of megahertz (MHz) or a gigahertz (GHz). Correspondingly, the optical coupling device also needs to operate at higher frequencies. [0004] The optical coupling device includes a light emitting element, a photodetector element and a switching circuit. Two vertical power MOS transistors (or MOS elements) of the switching circuit are connected to each other by a bonding wire providing a connection between the respective sources of the two MOS transistors. Even when the device is adapted to achieve higher speed, the bonding wire is still used for the connection between the sources of the two vertical MOS elements. [0005] However, the bonding wire that provides the connection between the two MOS elements of the switching circuit of a conventional optical coupling device has an inductance which depends on the diameter and the length of the bonding wire. When an attempt is made to pass a high-speed signal through a signal transmission path having the switching circuit, the bonding wire has noticeable inductance components, which cause the problem of degrading the quality of a waveform as the high-frequency characteristics, that is, the problem of rendering it difficult to transmit the high-speed signal. SUMMARY OF THE INVENTION [0006] Aspects of the invention relate to an improved optical coupling device. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1A is a perspective view of an optical coupling device in accordance with a first embodiment. FIG. 1B is a cross sectional view of the optical coupling device taken along A-A line in FIG. 1A. [0008] FIG. 2 is an equivalent circuit diagram of the optical coupling device in accordance with the first embodiment. [0009] FIG. 3 is a cross sectional view of the optical coupling device taken along A-A line in FIG. 1A. [0010] FIG. 4 is a perspective view of an optical coupling device in accordance with a second embodiment. [0011] FIGS. 5A and 5B are bottom views of the optical coupling device in accordance with the second embodiment. [0012] FIG. 6A is a perspective view of an optical coupling device in accordance with a third embodiment. FIG. 6B is a cross sectional view of the optical coupling device taken along B-B line in FIG. 6A. [0013] FIG. 7 is an equivalent circuit diagram of the optical coupling device in accordance with the third embodiment. [0014] FIG. 8A is a sectional view of the optical coupling device in accordance with the third embodiment. FIG. 8B is a diagram showing a characteristic impedance of a signal wire in the optical coupling device in accordance with the third embodiment. [0015] FIG. 9 is a voltage wavelength of the optical coupling device with a base board and without the base board. [0016] FIG. 10 is a perspective view of an optical coupling device in accordance with a fourth embodiment. [0017] FIG. 11 is a perspective view of an optical coupling device in accordance with a fifth embodiment. [0018] FIG. 12 is a perspective view of an optical coupling device in accordance with a sixth embodiment. [0019] FIG. 13 is a cross sectional view of the optical coupling device taken along C-C line in FIG. 12. [0020] FIG. 14 is an equivalent circuit diagram of the optical coupling device in accordance with the sixth embodiment. Continue reading about Optical coupling device... Full patent description for Optical coupling device Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Optical coupling device patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Optical coupling device or other areas of interest. ### Previous Patent Application: Systems and methods for reducing the influence of plasma-generated debris on the internal components of an euv light source Next Patent Application: Secure tag coding Industry Class: Radiant energy ### FreshPatents.com Support Thank you for viewing the Optical coupling device patent info. 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